/*
 * Fundamental constants relating to TCP Protocol
 *
 * Copyright (C) 1999-2019, Broadcom.
 *
 *      Unless you and Broadcom execute a separate written software license
 * agreement governing use of this software, this software is licensed to you
 * under the terms of the GNU General Public License version 2 (the "GPL"),
 * available at http://www.broadcom.com/licenses/GPLv2.php, with the
 * following added to such license:
 *
 *      As a special exception, the copyright holders of this software give you
 * permission to link this software with independent modules, and to copy and
 * distribute the resulting executable under terms of your choice, provided that
 * you also meet, for each linked independent module, the terms and conditions
 * of the license of that module.  An independent module is a module which is
 * not derived from this software.  The special exception does not apply to any
 * modifications of the software.
 *
 *      Notwithstanding the above, under no circumstances may you combine this
 * software in any way with any other Broadcom software provided under a license
 * other than the GPL, without Broadcom's express prior written consent.
 *
 *
 * <<Broadcom-WL-IPTag/Open:>>
 *
 * $Id: bcmtcp.h 700076 2017-05-17 14:42:22Z $
 */

#ifndef _bcmtcp_h_
#define _bcmtcp_h_

#ifndef _TYPEDEFS_H_
#include <typedefs.h>
#endif // endif

/* This marks the start of a packed structure section. */
#include <packed_section_start.h>

#define TCP_SRC_PORT_OFFSET 0  /* TCP source port offset */
#define TCP_DEST_PORT_OFFSET 2 /* TCP dest port offset */
#define TCP_SEQ_NUM_OFFSET 4   /* TCP sequence number offset */
#define TCP_ACK_NUM_OFFSET 8   /* TCP acknowledgement number offset */
#define TCP_HLEN_OFFSET 12     /* HLEN and reserved bits offset */
#define TCP_FLAGS_OFFSET 13    /* FLAGS and reserved bits offset */
#define TCP_CHKSUM_OFFSET 16   /* TCP body checksum offset */

#define TCP_PORT_LEN 2 /* TCP port field length */

/* 8bit TCP flag field */
#define TCP_FLAG_URG 0x20
#define TCP_FLAG_ACK 0x10
#define TCP_FLAG_PSH 0x08
#define TCP_FLAG_RST 0x04
#define TCP_FLAG_SYN 0x02
#define TCP_FLAG_FIN 0x01

#define TCP_HLEN_MASK 0xf000
#define TCP_HLEN_SHIFT 12

/* These fields are stored in network order */
BWL_PRE_PACKED_STRUCT struct bcmtcp_hdr {
    uint16 src_port;          /* Source Port Address */
    uint16 dst_port;          /* Destination Port Address */
    uint32 seq_num;           /* TCP Sequence Number */
    uint32 ack_num;           /* TCP Sequence Number */
    uint16 hdrlen_rsvd_flags; /* Header length, reserved bits and flags */
    uint16 tcpwin;            /* TCP window */
    uint16 chksum;            /* Segment checksum with pseudoheader */
    uint16 urg_ptr;           /* Points to seq-num of byte following urg data */
} BWL_POST_PACKED_STRUCT;

#define TCP_MIN_HEADER_LEN 20

#define TCP_HDRLEN_MASK 0xf0
#define TCP_HDRLEN_SHIFT 4
#define TCP_HDRLEN(hdrlen) (((hdrlen)&TCP_HDRLEN_MASK) >> TCP_HDRLEN_SHIFT)

#define TCP_FLAGS_MASK 0x1f
#define TCP_FLAGS(hdrlen) ((hdrlen)&TCP_FLAGS_MASK)

/* This marks the end of a packed structure section. */
#include <packed_section_end.h>

/* To address round up by 32bit. */
#define IS_TCPSEQ_GE(a, b) ((a - b) < NBITVAL(31)) /* a >= b */
#define IS_TCPSEQ_LE(a, b) ((b - a) < NBITVAL(31)) /* a =< b */
#define IS_TCPSEQ_GT(a, b) !IS_TCPSEQ_LE(a, b)     /* a > b */
#define IS_TCPSEQ_LT(a, b) !IS_TCPSEQ_GE(a, b)     /* a < b */

#endif /* #ifndef _bcmtcp_h_ */
